This is just on the shore of the lake. To go into the water, go to Merpeople Kingdom.
Aerion and Apollo
「 Apollo Liu 」Sixth Year Hufflepuff • Soft Boy
When he was stressed out by classes and fellow students, Apollo liked to take a walk by the Black Lake. Finding the lake's scenic beauty to be incredibly calming for him and it being a perfect time for him to clear his head. Aerion just so happened to be perched in a tree that Apollo would frequently walk by. As he walked by the lake and looked around at the highland views surrounding him, Apollo noticed a foot dangling from the branch and went over to investigate it. "Aerion? Is that you?" He asked once he was standing at the roots of the tree.